This application is based upon Disclosure Document No. 453,644, filed Mar. 26, 1999 of Tom Peterson, entitled xe2x80x9cTHE LASER BORE SIGHT ALIGNMENT AIDxe2x80x9d.
The present invention relates generally to an improved bore sighting assembly for accurately positionably mounting an optical sight such as a telescopic sight on a firearm, with the sighting assembly employing a laser beam generator for passing a coherent beam of light through the bore of the firearm and onto the surface of a remotely positioned target. The point on the target upon which the coherent beam impinges represents a direct projection of the bore of the firearm, and hence a theoretical point of impact without regarding gravitational and other external forces. By adjusting the reticles on the telescopic sight relative to the theoretical point of impact, and by determining the ballistic characteristics of the ammunition to be employed, the telescopic sight may be xe2x80x9czeroed-inxe2x80x9d for the actual point of impact for the firearm at any desired range. The bore sighting assembly of the present invention has been found to be exceptionally accurate, and thus sportsmen, competitive shooters, and the like are able to adjust the firearm sight in advance of entering the field where ultimate final adjustments and xe2x80x9czeroingxe2x80x9d may be undertaken.
In the past, various techniques have been employed for bore-sighting firearms, in particular, rifles. This is particularly necessary when the rifle is being fitted with telescopic sights. Bore sighting has proven to be a somewhat inexact science, since the gunsmith or technician may create errors due to the nature of limitations inherent in conventional bore sighting techniques and devices. The availability of some types of radiant energy, particularly in the form of visible light has provided some advancements in the ease and accuracy of bore sighting, however most currently known techniques have significant limitations and have not proven to be either expedient or substantially reliable.
The features of the present invention overcome prior limitations in that the improved bore sighting assembly makes it possible to accurately position a laser generator within any of a wide variety of firearms, with the generator being centered within an assembly in actual physical contact with the breech and bore of a rifle. Thus, the beam of coherent light is able to pass throughout the entire length of the barrel without impingement on the bore surface, and onto a remotely positioned target. By lining up the sight with the remote projection of the barrel bore, the positioning of the sight may be predetermined with significant accuracy.
The bore sighting assembly of the present invention is designed to be compatible with conventional laser generators which are battery powered, inexpensive, and widely commercially available. By carefully positioning such a laser source within the bore sighting assembly of the present invention, accurate telescopic sight mounting is made possible.
In accordance with the present invention, the firearm bore sighting assembly employs a laser generator for creating a coherent beam of monochromatic light energy with the beam passing through the barrel having a diameter less than that of the firearm bore. The firearm bore sighting assembly employs a source of coherent monochromatic light, commonly known as a laser generator, with the coherent beam of monochromatic light having and maintaining its certain predetermined narrow beam diameter. Beam directing or guide means are provided for mounting the generator in an assembly wherein the beam is centered within and passes directly through the firearm bore without interference due to impinging on the wall of the bore. The beam directing means is also adjustable for retaining the generator in a proper radial disposition, and in order to further control the beam diameter, a beam transmitting orifice formed within a disc is placed along the beam path. After passing through the orifice, the coherent beam is then passed through the firearm bore.
The beam directing means further includes an elongated tubular beam guide which is configured to be adjustably and firmly positioned within the firearm receiver. A frusto conical orienting tip is provided at the distal end of the tube, with the frusto conical tip having a central light beam transmitting bore through which the beam travels for centering the beam. The size of the frusto conical tip is controlled to accurately position the actual tip centrally within the firearm bore. As a further feature, the body of the frusto conical tip is formed of a translucent material, and deflection of the coherent beam from a true axial direction will cause the edge portion of the coherent beam to strike the frusto conical tip, and thereby illuminate the entire tip indicating to the technician that the position of the generator must be further adjusted. Upon adjustment of the light beam within the beam guide, the path of the beam may be corrected so as to avoid contact with any portion of the frusto conical tip. When properly adjusted, and when the beam does not strike any portion of the tip, the translucent characteristic of the tip will verify this condition by simply ceasing to glow with the characteristic color of the beam.
As a further feature of the present invention, a range aid is provided which is adapted to be coupled to the eyepiece of the telescopic sight, with the range aid including horizontally disposed lines which, taken together with ballistic characteristics of the ammunition being used, can aid in accurately positioning the sight for zeroing at a predetermined range. This is all accomplished by means of the same remotely positioned target. The remote target is preferably positioned a distance of approximately 25 yards from the muzzle of the firearm, although any desired distance in excess of about 20 yards is usable.
A further feature of the invention includes the utilization of a muzzle adaptor which permits the device to be employed on firearms with larger bores, including shotguns as well as certain rifles of large bores.
Therefore, it is a primary object of the present invention to provide an improved bore sighting assembly for assistance in accurately positionably mounting an optical or telescopic sight on a firearm, particularly on rifles.
It is a further object of the present invention to provide an improved bore sighting assembly which employs a source of laser energy for passage of a beam of coherent light unimpeded through a firearm bore, and onto a remote target, where the optical sight may be used to observe the illuminated spot in order to mount the scope based upon the point at which the coherent light energy strikes the target.
It is yet a further object of the present invention to provide an improved bore sighting assembly for accurately and positionably mounting a telescopic sight on a firearm, wherein means are provided for accurately positioning a laser generator within the receiver area of a rifle, and wherein the coherent light energy created by the generator is passed through the barrel bore and onto a remotely positioned target where the reticle portions of the telescopic sight may be positionably directed for viewing the point of projection for accurate mounting of the telescopic sight.
Other and further objects of the present invention will become apparent to those skilled in the art upon a study of the following specification, appended claims, and accompanying drawings.